The nest is built of wetland vegetation, either on an elevated piece of land or floating on shallow water in marshland, and usually two eggs are laid.

[5] Although the bird is not considered endangered over the majority of its range, populations are showing some decline, especially in southern Australia, and local action plans are being undertaken in some areas.

[7] When first described by the naturalist George Perry in 1810, the brolga was misclassified as a species of Ardea,[3] the genus that includes the herons and egrets.

[8] Ornithologist John Gould used the name Grus australasianus when he wrote about it and noted it to be widespread in the north and east of Australia.

[4] The Royal Australasian Ornithologists Union made brolga, a popular name derived from Gamilaraay burralga, the official name for the bird in 1926.

[11] In the resulting rearrangement to create monophyletic genera, four species, including the brolga, were placed in the resurrected genus Antigone that had originally been erected by German naturalist Ludwig Reichenbach in 1853[8][12] Two subspecies were suspected to exist: A. r. argentea found in Western Australia, the Northern Territory and western Queensland and A. r. rubicunda, occurring in New Guinea, Queensland, New South Wales, Victoria, and South Australia.

[14] The adult has a grey-green, skin-covered crown, and the face, cheeks, and throat pouch are also featherless and are coral red.

The gular pouch, which is particularly pendulous in adult males, is covered with such dense bristles as to make it appear black.

The ear coverts appear as a grey patch of small feathers surrounded by red naked skin and the body plumage is silvery-grey.

[17] The brolga is the heaviest flying bird regularly found in mainland Australia, averaging slightly higher in body mass than other large resident species such as black swan, Australian pelican and the Australian race of sarus crane (Asian sarus cranes are heavier and significantly taller).

The brolga is more silvery-grey in colour than the sarus, the legs are blackish rather than pink, and the trumpeting and grating calls it makes are at a lower pitch.

[19] Brolga movements in Australia are poorly understood, though seasonal flocks are observed in eastern Queensland in nonbreeding areas regularly, and a few coastal populations are suspected to move up to 500 km (310 mi) inland.

At this time, southern populations congregate in inland flocking areas, which include upland marshes, the edges of reservoirs and lakes, pastures, and agricultural land.

When rain arrives in June and July, they disperse to the coastal freshwater marshes, shallow lakes, wet meadows, and other wetlands where they breed.

In the nonbreeding season, they gather into large flocks, which appear to be many self-contained individual groups rather than a single social unit.

[5] In south-western Queensland, 26–40% of all crane sightings were breeding pairs and families in the Gilbert and Flinders river floodplains.

The bird's black wingtips are visible while it is in the air, and once it gathers speed, its flight is much more graceful and it often ascends to great heights.

[23] They also eat the shoots and leaves of wetland and upland plants, cereal grains, seeds, insects, mollusks, crustaceans, frogs, and lizards.

[9] Isotopic analyses of molted feathers in their breeding grounds along the Gulf of Carpentaria showed their diet to be diverse across multiple trophic levels, with minimal contribution of vegetation.

The male stands alongside in a similar posture, but with his wings flared and primaries drooping, which is the only time when sex can be differentiated reliably.

The bird then jumps a metre (yard) into the air with outstretched wings and continues by stretching its neck, bowing, strutting around, calling, and bobbing its head up and down.

The nest, which is built by both sexes, is a raised mound of uprooted grass, and other plant material sited on a small island in shallow water, or occasionally floating.

[28] The suspected chief threats faced by the brolga, particularly in the southern part of its range, are habitat destruction particularly spread of blue gum (Eucalyptus globulus) into breeding habitats, the drainage of wetlands, collision with powerlines, burning and grazing regimes, spread of invasive species, and harvesting of eggs.

[6] It is more secure in the north-eastern part of its distribution range as the floodplains of Queensland are mostly unsuitable for farming and much of it is in private ownership, but development activities that change or reduce habitat diversity, especially in the Gulf Plains, can have unknown impacts on their populations.

[26] Conservation measures being undertaken include international cooperation, legal protection, research, monitoring, habitat management, education, and the maintenance of captive flocks for propagation and reintroduction.